Bra Size Calculator
Find your bra size in two measurements. Enter your underbust and bust in inches or cm, and the calculator gives your UK/Pakistani size (like 34B) and two sister sizes to try.
How to measure
Use a soft measuring tape and wear a non-padded bra, or measure without one. Stand straight and breathe normally.
- 1
Underbust
Wrap the tape snugly around your ribcage, right under the bust. Keep it level all the way round and write the number down.
- 2
Bust
Wrap the tape loosely around the fullest part of the bust, parallel to the floor, without pressing in.
- 3
Calculate
Enter both numbers. Measure twice if a number looks off; a half inch either way can change the cup.
How it works: band = underbust rounded to an even number (an odd number rounds up, so 33 becomes 34). Cup = bust minus band, one letter per inch: 1 inch A, 2 B, 3 C, 4 D, 5 DD, 6 E, 7 F.
Bra size chart (inches)
| Underbust (inches) | Band |
|---|---|
| 27 to 28 | 28 |
| 29 to 30 | 30 |
| 31 to 32 | 32 |
| 33 to 34 | 34 |
| 35 to 36 | 36 |
| 37 to 38 | 38 |
| 39 to 40 | 40 |
| 41 to 42 | 42 |
| Difference | Cup (UK) |
|---|---|
| Under 1/2 inch | AA |
| 1 inch (2.5 cm) | A |
| 2 inches (5.1 cm) | B |
| 3 inches (7.6 cm) | C |
| 4 inches (10.2 cm) | D |
| 5 inches (12.7 cm) | DD |
| 6 inches (15.2 cm) | E |
| 7 inches (17.8 cm) | F |
| 8 inches (20.3 cm) | FF |
| 9 inches (22.9 cm) | G |
Example: underbust 31 inches gives a 32 band; bust 35 inches is 3 inches more, so the size is 32C. Sizes vary by brand, so check the brand's own chart too.
Questions
Why don't you add 4 inches to the underbust?
The old method added 4 or 5 inches to the underbust to get the band (30 became 34). It was made for older bras with little stretch. Most brands now use the underbust itself, rounded to an even number, because the +4 method tends to give a band that is too big and a cup that is too small. If a brand's chart still uses +4, follow that brand's chart for its bras.
Are Pakistani bra sizes the same as UK sizes?
Mostly yes. Shops in Pakistan use the same band numbers (28, 30, 32, 34, 36, 38, 40) and cup letters A, B, C and D. Above D, brands differ: UK brands go DD, E, F, FF, G, while US sizes go DD, DDD. Check the letters on the brand's chart.
Can I measure in cm?
Yes. Switch the calculator to cm. It converts to inches (1 inch = 2.54 cm) and uses the same rules, so 81 cm underbust gives a 32 band.
What are sister sizes?
Sizes with the same cup volume on a different band. Going down a band size means going up a cup letter: 34B, 32C and 36A hold the same volume. Try a sister size when the cups fit but the band feels too tight or too loose.
How should the right size feel?
The band sits level all round and stays put when you lift your arms. The cups are filled without gaps or spilling over. The straps carry only a little of the weight and don't dig in. A new bra should fit on the loosest hook, so you can tighten it as it stretches.
Nightwear that fits
NightyDress.pk sells nighty dresses, bridal nighty and pajama sets for women across Pakistan, with cash on delivery.